The Siemens Desiro is a family of diesel or electricmultiple unit passenger trains developed by Siemens Mobility, a division of the German Siemens AG conglomerate.[1] The main variants are the Desiro Classic, Desiro ML, Desiro UK and the later Desiro City, Desiro HC and Desiro RUS. The trains are mostly used for commuter and regional services,[1] and their rapid acceleration makes them suitable for services with short distances between stations. The design is flexible, and has become common in many European countries.

In 2005 and 2006, the Bulgarian State Railways began operating Desiro trains as part of a 67 million Euro deal with Siemens AG for a total of 25 Diesel multiple units.[2] As of 22 March 2006, 16 trains had been delivered, with many of them operating on the Sofia-Kyustendil-Sofia line. Another 117 million Euro deal for 25 EMUs has also been signed with Siemens AG. The EMUs were fitted out in Varna, where BDZ and Siemens AG are intending to establish a joint venture company. The EMUs are designated classes 30 and 31 and are servicing traffic in the Sofia and Plovdiv areas.

In Denmark DSB has rented 12 Desiro trains since 2002. The trains are primarily used between Odense and Svendborg and between Odense and Fredericia.
On 2 July 2009 DSB signed a contract of eight trains from Siemens for Grenaabanen, which entered service on 12 December 2010, with an option for 92 more.[4] The trains extend to Odder from December 2012, starting the light rail network in Aarhus city.[5]

Nordjyske Jernbaner used Desiro trains since 2004 on all its operations. Today the company owns eight Desiro trains.

Germany's Deutsche Bahn introduced two-car Desiro DMUs for local services in 2000. With a top speed of 120 km/h (75 mph), these Class 642 units are mainly used on branch lines and regional lines. Besides the 234 units purchased by DB in 2007, various private German rail companies are also using Desiro DMUs.

The Class 642 is equipped with two MTU diesel engines with an output of 275 or 315 kW (369 or 422 hp) each and hydro-mechanical transmission with retarders. It typically contains 100 seats. When linked together with Scharfenberg couplers, up to three trainsets can be operated together. The Desiros are quite popular with most passengers, thanks to their good acceleration. Because they have often replaced push/pull trains, their shorter journey times, such as on the Müglitz Valley Railway, have encouraged greater passenger numbers.

Originally DB intended to operate together modern DMUs purchased from different manufacturers, but due to software incompatibilities this proved to be impossible. Therefore, the Class 642 can only be mechanically coupled with other DMUs like the Class 643.

In Greece eight diesel DMU-2 Desiro trains (OSE class 660) were temporarily in service with the Hellenic Railways Organisation (OSE) during 2004–2006, and again in 2007 on the Athens–Chalkida line and on the Athens suburban railway lines (Proastiakos). Afterwards they were returned to their owner (Hellenic Shipyards S.A.) in December 2007. In the late 2008 Hellenic Shipyards/MAN-FERROSTAAL leased the eight units to Hungary with a contract for 20 years.[6]

At present 31 diesel Desiros are in service with MÁV (including the eight units from Greece), mainly as suburban trains on the regional line between Budapest-Esztergom and Budapest - Lajosmizse and as an InterCity between Budapest and Baja. On weekends the units also used as peak inter-city trains from Budapest to Baja and Sátoraljaújhely and as fast trains from Budapest to Tapolca. During the summer months (when fewer units are used on the Budapest suburban routes) Desiros appear on some local train diagram on the north shore of the Lake Balaton.

The 57 km (35 mi) Express Rail Link line, an airport rail link service between KL Sentral railway station in central Kuala Lumpur and Kuala Lumpur International Airport to the south, uses the Desiro ET 425 M four-car Electric Multiple Units (which are technically similar to DBAG Class 425 sets in Germany).[7] 12 trainsets are currently in operation: Eight trains are used for the non-stop KLIA Ekspres service between KL Sentral and the airport, while another four trains call at three intermediate stations in between, including one serving Putrajaya. These EMUs have a maximum commercial speed of 160 km/h (99 mph) making them the fastest trains currently operating in Malaysia.

Căile Ferate Române (CFR), Romania's national railway operator, is one of the largest users of the Siemens Desiro trainsets (as the light train variant). CFR, which is currently undergoing modernisation, has bought 120 diesel Desiro trainsets and uses them for both its "Inter Regio", and "Regio" services, but mainly on its "Regio" trains. The trains are nicknamed "Săgeata Albastră" (Blue Arrow). There was some criticism of the use of Desiros for CFR's long-distance services because they were considered to be uncomfortable. CFR has recently refitted them, and is now using Desiros mainly on its medium- and short-distance routes. For example, it is planning to use them as part of a proposed commuter link in Bucharest and Ilfov county. In 2018, CFR announced that they plan to purchase 100 more Desiros, second hand.[8] For more information on routes, see Căile Ferate Române.

In 2008 NMBS/SNCB ordered 95 Desiro ML trains, with options for up to 300.[10] In 2013, the order of the final 250 trains was suspended because of technical problems with the trains already running. The company is seeking damages from Siemens for these problems which caused many delays. Siemens had already been fined €25 million for the late delivery of the first batch of trains.[11] The order for all units was confirmed in 2013 and in March 2015 the last two arrived.

In August 2014 the head of the NMBS/SNCB explained to the newspapers that the Desiro trains need repairing too often, i.e., at a rate of one technical intervention per 8000 kilometers.[12] The trains are used heavily on the Brussels Regional Express Network, but also InterCitylines between Antwerp and Ghent and on lines with lower voltage in the Belgian Ardennes where they replaced diesel-trains.

Desiro ML Mittelrheinbahn is used by the private rail operator trans regio for regional services between Cologne and Mainz on the left bank of the Rhine.[13] The EMUs are leased from Angel Trains and received the class number 460 by the Eisenbahnbundesamt, the federal railway authority (the unpowered middle carriages have the class number 860). The 15 kV ACoverhead line EMUs have a top speed of 160 km/h (99 mph); however they are limited by the EBA to 150 km/h (93 mph) on account of insufficient braking power from 160 km/h (99 mph). All cars use conventional bogies and additional middle carriages can be added later.

In January 2013 RZD began putting into service the first 18 trains from the initial order for 38. In mid-2013 a joint venture between Siemens and Ural Locomotives began production of the second batch of 16 trains at a factory in Ekaterinburg. The first train was assembled in June 2014. 62% of its components were produced locally. The factory is expected to supply 240 trains by 2021.[15]

In 2011 RZD ordered 1,200 cars from Ural Locomotives. Local content is to be increased to 80 percent. Siemens also has an order for maintenance of rolling stock for a period of 40 years. The contracts with the Siemens is estimated at 2.5 billion euros.

Siemens uses the name Desiro UK for the DMU and EMU trains operated by various United Kingdomtrain operators. These trains have a completely different design to the lighter Desiro Classic variant. The trainsets have modern equipment such as toilet waste retention tanks, ergonomic seats, and automated information displays with spoken announcements.

The first electric Desiro UK units were ordered by South West Trains for both short and long distance service out of London Waterloo to Alton, Basingstoke and the Hampshire/Dorset coast, to replace its Mark 1 slam door EMUs, which were due for replacement as most were more than 40 years old and did not meet modern health and safety requirements. They became two different classes, both of which use the 750 V DC third-rail power supply. One hundred and ten Class 450 four-car units for commuter services entered service in 2003, and 45 Class 444 five-car units for long-distance inter-city services entered service in 2004. An additional order for a further 17 Class 450 units was placed, with the trains in service by late 2006 and early 2007.

As part of the modernisation of the West Coast Main Line, the former Strategic Rail Authority ordered 30 Class 350 dual-voltage sets for use on stopping services.[when?] They are operated by West Midlands Trains. These units were originally ordered as Class 450 third-rail units for South West Trains, but following a review by the Strategic Rail Authority they were diverted to the West Coast. The dual-voltage capability has only been used in service on temporary loan to Southern on Milton Keynes Central – East Croydon services whilst covering for a shortfall of Southern Class 377Electrostar units. The units have been praised for their air conditioning, accessibility and performance, but criticised for their comfort (newer units have 3+2 seating). Thirty Class 350/1 four-car units entered service in 2005, and in 2008/9 a further 37 Class 350/2 four-car units entered service.

On 11 July 2008, First ScotRail ordered a number of Class 380 EMUs for delivery in 2010. The order was for 22 three-car and 16 four-car units.[17] Entry to service began 8 December 2010. They replaced the Class 318 and Class 334 "Juniper" fleets on the Inverclyde Line and Ayrshire Coast Line. The Class 322 trains on the North Berwick line were also replaced by the new units.

To fulfil their franchise commitment, First TransPennine Express ordered the first diesel variant of the Desiro UK for use on its inter-city services across the north of England and over the border in southern Scotland. 51 three-car units designated as Class 185 entered service in 2006.

At InnoTrans 2014, Siemens presented its Desiro High Capacity (Desiro HC) offering. The Desiro HC consists of single deck motor cars with up to three intermediate double deck coaches, which combines accessibility with capacity.

In September 2017, Israel Railways announced that Siemens was the successful bidder in a tender for 60 Electric Multiple Unit sets (for a total of 330 carriages) to be delivered starting in 2020. Under the contract, Siemens will supply Israel Railways with Desiro HC trainsets at a value of US$910 million with options for additional units to be supplied in the future. Siemens will also build a $65 million maintenance depot in Ashkelon and maintain the first 24 trains for the sum of $114 million, with an option for Israel Railways to increase the number of trains under Siemens’ maintenance later.[21][22]